Illuminating device for microscopes



Jam. 12, 1932. H. HEINE 1,840,448

ILLUMINATING DEVICE FDR MICROSCOPES Filed Jan. 25, 1950 Fig 1 Hg. 5.

INVENTOR Patented Jan. 12, 1932 UNITED STATES PATENT; OFFICE HEBMANN HEINE, OI 'W'ETZLAB, GERMANY, ASSIGN OR TO THE FIRM ERNST LEITZ,

OP'IISCHE WEBKE, OF WE'IZIQAB, GERMANY I ILLUIINATING DEVICE FOR MICBOSCOPEB Application nledJanual-y 25, 1930, Serial No. 423,583, and in. Germany January 81, 1989.

. This invention relates to an improved illummatmg devlce for microscopes.

For many purposes 1t 1s necessary to illuminate objects under microscopic exami- 5 nation by incident light, i. e. by light rays berkiihn reflector necessitating the transmis-v sion of light from below the object which had to be backed by an opaque ground or stop and the vertical illuminators requiring somewhat particular adjustment of the li ht and being liable to cause some confusion etween the illuminating rays and those forming the image.

The device accordin to the present invention is free from su a disadvantages and afiords a very eflicient means for the examination of objects by incident light.

The improved illuminating device com- Y prises a condenser surrounding the objective above or behind the objective an and a prism or other reflecting element the condenser, the arrangement being such that light is reflected through the condenser and thereby is caused to converge on to the object, the path of such illuminating light rays before they enter the condenser being external to the image-forming optical system.

The condenser itself may be of known type such as is. used, in quite a'diflerent way, for dark field illumination- Preferably the condenser is mounted to surround the objective that it is adjustable 1 coaxially therewith so that -its focal point need not always coincide with that of the objective but may, for instance, be lower. This is advantageous, for example, in examining more or less transparentobjects or objects rendered so by immersion in oil or other fluid, as the object can then be illuminated by diffused light.

In the accompanying drawings. which are diagrammatic,

Figure 1 is a central vertical section' through one form of illuminating device according to this invention,

Figure 2 is a sectional plan on the line 22 of Figure 1,

Figure 3 is a view similar to Figurel but showing a modified construction of illuminating device also according to this invention, and

Figure 4 is a sectional plan on the line 44 of Figure 3.

Referring now to Figures 1 and-2, A is a condenser mounted so as to surround an objective B suspended from the bottom plate of a box or casing C attached to the lower end D of the body tube of a microscope. The casing G contains a reflecting surface E. with a central .space, this surface being disposed between the cemented surface of two lass prisms F and F The lefthand side 0 the casing C in Figure 1 is open to admit light from an outside source to the reflecting surface E, the central rays being blocked by a screen G. At the righthand side of the casing G is an opening C through which any subsidiary light can pass out.

The 21th of the illuminating rays is in-. dicated y the arrows. The rays are reflected downwards as a column of light surrounding the objective B and into the condenser A and are caused by said condenser to converge on to the object under examination. In this construction the condenser is intended to be fixed in any convenient way relatively to the objective, the focal point of the condenser preferably coinciding with that of the ob ective.

As will be seen from Figure 2, the bottom plate 0 of the casing C has segmental openings C through which .theilluminating rays ass. The image-formin rays from t e o ective B pass up throug the central aperture G and throu h the clear space in the reflecting surface ference by the illuminating re s. v

The construction illustrate in Figures 3 1 and 4, while following the same principles,

differs in some of its details from the construction illustrated in F1 res 1 and 2. The prisms ar'e dispensed wi and the reflector entirely free from intering 0 a screen C servin to block out the central rays from the outside source of light when the screen J is not in use.

In this construction the condenser A is carried in a screwthreaded mounting A en- -gjaging with a similarly screwthreaded sleeve at the bottom of the casing C. Thus, by rotating the condenser it can be raised or lowered relatively to the objective B which it surrounds. By this means the focal point of the condenser can be brought below that of the objective B somewhat as. indicated in Figure 3, this afiording an illumination of the object by difi'used light, which is very desirable in some cases.

As in the construction previously described with reference to Figures 1 and 2, the path of the illuminating rays is exterior to that of the image-forming raysfrom the objective, and there is thus no risk of confusion or interference between those two sets of rays.

Figure 4 shows the segmental o' nings C in the bottom plate of the casing a through which openings the illuminating rays can pass to the condenser whilst the image-forming rays pass up through the central aperture C".

I claim 1. In an illuminating device for microscopes, a casing, an objective suspended from said casing and a condenser surrounding said objective, attached to the lower end of a microscope, a bottom plate for said casing having segmental openings through which the illuminating rays pass, and a central opening allowing the passage of the imageformmg rays from said objective without mterference by the illuminating rays.

2. In an'illuminating device for microscopes, a casing, a reflector having a central space and supported in said casing, a screenmg tube passing down through the space in said reflector, a detachable and rotatable azimuth screen on one side of the casing and hav1ng an aperture, a screenowithin said 'casing for blocking out the outside central rays, when said azimuth screen is not used,

a threaded sleeve at the bottom of the casing,

a condenser, and an objective surrounded by said condenser, a threaded sleeve for said condenser engaging said casing sleeve to allow rotation of said condenser to raise and lower the same relatively to the objective to bring the focal point of the condenser. below that of the objective affording an illumination of the object to be examined by different 3. In an illuminating device for microscopes, a casing, an objective suspended from said casing, and a condenser surrounding said iao 

